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Dmitry Romanov edited this page Jun 28, 2024 · 16 revisions

CCDB provides 'ccdb' - command line interface for introspection and management of constants. It can be used as interactive shell or to execute single commands.

Example. Single command:

       (1)                           (2)  (3)
ccdb -c "mysql://john@localhost:999" ls /TOF/params
  1. -c "mysql://john@localhost" - is ccdb global CCDB argument, which sets the connection string.
  2. ls - is a ccdb command which (like a POSIX ls) prints a list of directories and tables belonging to /TOF/params
  3. /TOF/params is an argument of the ls command.

Example. Interactive session:

ccdb -c "mysql://john@localhost:999" -i                  (1)
> ls /TOF/params                                         (2)
> help                                                   (3)
> cd /TOF                                                (4)
> cd params
> ls
> pwd                                                    (5)                                              
> q                                                      (6)
  1. flag -i starts ccdb in the interactive mode.

  2. ls /TOF/params - the result is exactly the same as in the above example.

  3. help command provides list of commands and how to use each of them

  4. ccdb interactive mode has a current working directory, with relative and absolute paths

  5. Same as for POSIX shell, pwd command shows the current directory.

  6. to exit interactive mode enter q, quit or press ctrl+D

Since ccdb objects have /name/paths and many other things that looks like POSIX file system, the commands are very posix-shell-like.



Connecting to DB

ccdb command uses the connection strings to connect to data source. The connection string should be provided by:

  1. -c <connection string> argument (see the above example) or by

  2. CCDB_CONNECTION environment variable

    export CCDB_CONNECTION=mysql://[email protected]/ccdb

If nothing is given by -c or CCDB_CONNECTION, then mysql://ccdb_user@localhost/ccdb is used.

NOTE: -c flag has the higher priority than CCDB_CONNECTION



Help system

ccdb is designed to be a self descriptive. By using help command one could get all the commands and how to use them. For historical reasons ccdb --help or ccdb command --help will not work, use ccdb help command

ccdb help        # List of existing commands and ccdb help
ccdb help cat    # Help for `cat` command
ccdb --help      # <= will not work
ccdb cat --help  # <= will not work or not how expected


Commands

Commands consistency

Command arguments are chosen to be consistent between commands. Some flags and argument formats means the same across all commands. CCDB has several classes of objects: directories, type tables, variations, run number, assignments. Some commands may be applied for different classes. For example 'info' command may be executed against directory, table or variation There are unified flags to identify objects for all commands:

  • -v - Variation
  • -t - Data table
  • -r - Run or run-range
  • -d - Directory
  • -a - Assignment (usually identified by request or db ID)

Example. Info command:

ccdb -i
> info -v default                                          (1)
> info -d /TOF                                             (2)
> info -t /TOF/params                                      (3)
> info /TOF/params                                         (4)
> dump -a 2                                                (5)
  1. Get information about "default" variation
  2. Get information about "/TOF" directory.
  3. Get information about "/TOF/params" type table
  4. By default 'info' treat non flag argument as a name of a table.
  5. Return a content of table with assignment db ID=2 (obtained by vers command)

Commands overview

This table is printed if one executes "ccdb help"

(command) (name) (description):
add AddData Add data constants
info Info Prints extended information about an object
vers Versions Show versions of data for the specified table
run CurrentRun gets or sets current working run
dump Dump Dumps datat table to a file
show Show Shows type table data
mkdir MakeDirectory Create directory
pwd PrintWorkDir Prints working directory
cd ChangeDir Change current directory
mktbl MakeTable Create constants type table
cat Cat Show assignment data by ID
ls List List objects in a given directory
log Log Get CCDB changes log
db DataBase Data Base management commands

Assuming that user is in interactive mode, one may categorize the commands:

To navigate directories

  • pwd - prints curent directory
  • cd - switch to specified directory
  • ls - list objects in the directory (wildcards are allowed)
  • mkdir - creates directory

Example. Directory commands overview:

    > pwd
	> cd /TOF
	> ls
	> mkdir constants
	> ls con*

Get information about objects

  • info - gets information about objects (use -v -r -d flags), see example 6.
  • vers - gets all versions of the table
  • cat - displays values
  • dump - same as cat but dumps files to disk
  • log - see logs information

Manage objects

  • mkdir - creates directory
  • mktbl - creates data table
  • add - adds data from text file to table (variation and runranges are created automatically by add command)

Deleting objects

While CCDB discourages to delete anything. Instead, one can deprecate tables, directories or variations, which are old and not used anymore. Deprecation removes tables/directories from listings (e.g. ls command) but if old code will request the constants, they will be available.

There are still cases, when removing something might be required:

  • It is possible to make a typo/mistake when creating a table/variation
  • On early development stage (introducing new constants and writing code, that uses it) it might be beneficial to recreate something (e.g. a table with different set of rows). CCDB warning: this already might lead to trouble(!) but in many cases with playground SQL it is OK.
  • For all other cases deletion is highly not recommended! Treat CCDB as a logbook - calibration data logbook. But still removing stuff is technically possible.

rm - command shell be used with common flags -d, -t, -v, -a to remove a directory, table, variation or assignment.

Directory/table/variation must be empty to be removed. Which means, one has to first delete all assignments from table to remove table, remove all tables to remove a directory, etc.